Vacuum drying apparatus.



0. S. SLEEPER.

VACUUM DRYING APPARATUS.

APYLIOATIOH FILED 11:11.14, 190B. BENBWBD MAY 1o, 191s.

1,073,872. Patented Sept. 23, 1913.

0. s. SLEBPER.

VACUUM DRYING APPARATUS.

APPLICATION FILED FEB.14, 1908. RBNEWBD MAY 10, 1913.

Patented Sept. 23, 1913.

SEIEETZ.

5 SHEETS l in 1 ifvzesfes.

0. S. SLEEPBR.

VACUUM DRYING APPARATUS.

APPLIOATION FILED rn.14,1soa. RENBWBD MAY 1o, 191s.

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VACUUM DRYING APPARATUS.

AlPLIoATIoN FILED P11311, 1908. RBNEWED MAY 1o. 1913.

Patented Sept. 23, 1913.

0. S. SLEEPER.

VACUUM URYING APPARATUS.

APILIOATION FILED PEB. 14, 190B. BENEWED MAY 10, 1913.

Patented Sept. 23, 1913.

UNITED sTATEs PATENT oEEroE.

OLIVER S. SLEEPER, OF BUFFALO, NEW YORK, ASSIGNOR 'TO BUFFALO FOUNDRYAND MACHINE COMPANY, OF BUFFALO, NEW YORK, A CORPORATION OF NEW YORK.

VACUUM DBYING APPARATUS.

Specification o! Lettere Patent.

Patented Sept. 23, 1913.

Application filed February 14, 190B, Serial No. 415,798- Benewed May 10,1913. Serial No. 766,891.

.To all whom it may concern:

Be it known that I, OLIVER S. SLEEPEB, a citizen of the United States,residing at Buffalo, 1n the county of Erie and State of New York, haveinvented a new and useful Improvement in Vacuum Drying Apparat-u8, ofwhich the following is a specification.

This lnvention relates to a continuous vacuum drier and has the objectto produce an improved machine of the character whereby a liquidsolution may be dried thoroughly and economically and with a mlnlmumexpenditure of heat, labor and power and which can be thoroughly andeasily cleaned.

In the accompanying drawings consisting of 5 sheets: Figure 1 is a sideelevation of my improved continuous vacuum drier. Fig. 2 is an endelevation of the same. Fig. 3 1s a vertical cross section in line 3 3,Fig. 1. Fig. 4 is a vertical longitudinal section taken 1n line 4 4,Fig. 3. Fig. 5 is a horizontal section taken in line 5 5, Fig. 3. Fig. 6is a fragmentary vertical transverse section, on an enlarged scale, inlinem 6 6, Fig. 4. Fig. 7 is a fragmentary vertical transverse sectionin line 7 7, Fig. 4, on an enlarged scale. Fig. 8 is a fragmentary topplan view, on an enlarged scale, of one form of my improved means ofdeliverinv the solution to be dried to the heating rum. Fig. 9 is afragmentary vertical longitudinal section showing a modication of themeans for agitating the 'solution to be dried and deliveringthe same tothe heating drum. Fig. 10 is a fragmentary vertical cross sectio-n ofthe same in line 10 l0, Fig. 9.

Similar letters of reference indicate corresponding parts throughout theseveral views. A

Referring to Figs. 1-8, A re resents the vacuum or drying chamber W ichis constructed generally in the form of a horizontal cylinder the upperpart of which is circular while the lower part thereof is constructed inthe form of a longitudinal trough the side walls a, a of which convergedownwardly. This chamber may be supported by any suitable means butpreferably by a frame having standards a1 as shown in the drawings.Lengthwise Within the vacuum chamber is arranged a horizontal hollowheating drum B which rotates vertically in the direction of the arrow inFig. 3 and is journaled by means of hollow trunnions Z), b1 whichproject outwardly from the heads at opposite ends of the drum and turnin bearmgs b2 b3 formed in the heads at opposite ends of the vacuumchamber. The rotation of this Cylinder may be etected by any suitablemeans. For the purpose of heating the drum a heating medium, preferablysteam, is conducted into the interior of the drum, this being preferablyeffected by means of a stationary supply pipe C arranged concentricallwithin the hollow front trunnion b of the rum and sup orted by a bracketD on the front head of t evacuum chamber, a stuiling hox al beinginterposed between this Steam supply pipe and the front truunion formaintaining a steam tight joint between these arts. The water ofcondensation is removed from the interior of the heating drum by means.of a stationary outlet pipe E arranged concentrically within the hollowrear trunnion and supported by a bracket c on the rear head of thevacuum chamber, a stufling box e1 arranged between the outlet pipe andthe reartrunnion for producing a steam tight joint between these parts,an oblique scoo F arranged lengthwise on the inner side o the heatingdrum with its front end in advance of its rear end, and an intel mediatepipe f lconnected at its outer end with the rear receding end of thescoop and connected at its inner end with the rear trunnion b1 andcurved in a direction opposite to that in which the heating drumrotates. During cach rotation of the drum any water of condensationwhich gathers within the lower part of the same is caught by the scoopand as the latter rises, this water is caused to flow from the front endto the rear end of the scoop owing to the inclination thereof and isthen carried by the intermediate pipe from the rear end of the scoopiniovthe discharge pipe.

Below the heating drum is arranged the nozzle whereby the solution to bedried is delivered to the underside of the heating drum. This nozzlecomprises a hollow tubular body or pipe G arranged lengthwise helow theheating drum and provided with a longitudinal outlet slot or throat gwhich is normally on the upper side of the body und faces the peripheryof the healing drum, a

wide delivery or distributing plate shelf H arranged on the tubular bodyin front of its slot and extending practically the full length of thedrum, a battle plate I arranged on the tubular body in rear of its slot,a rib z arranged on the upper side of the baffle plate, and guard ribsor anges j arranged transversely on the upper side of the distributingshelf at opposite ends thereof. 'The body of the nozzle extends at itsfront and rear ends through stuiiing boxes g1, g2 on the front and rearheads of the vacuum chamber which stuiing boxes form bearings in whichthe nozzle may turn for convenience in cleaning the solution deliverydevice. In the operative position of the nozzle its front shelf isarranged concentrically with the' heat-ing drum, as shown in Figs. 3 and7, and is separated by an intervening space from the periphery of t-heheating drum. The baiiie plate I is separated from the distributingplate by a narrow intervening slit h and its rib z' extends nearer tothe periphery of the heating drum than the distributing plate, therebyforming a dam which prevents the solution from flowing backwardly fromthe nozzle.

Theguard ribs j prevent the solution from escaping at the ends of thedistributing plate or shelf and reaching'the end heads of the drum whichcannot be readily cleaned or scraped. The several parts of the deliverynozzle thus produce a basin or tray the upper concave side of whichfaces the periphery of the drum and forms with the latter a narrowpassage way or intervening space. The solution to be dried passes fromthe tubular body upwardly through its outlet slot and through the slitbetween the bailie plate and distributing plate, and thence forwardly inthe form of a shallow stream between the upper side of the distributingplate and the underside of the heating drum. The solution at this timeis prevented from passing backwardly over the delivery nozzle owing tothe dam on the rear part of the nozzle which is higher and extendscloser to the periphery of the heating drum than the distributing plate.As the drum rotates forwardly in "contact with the stream of solutionflowing in the same direction over the distributing plate, a thin filmof this solution adheres to the drum, this deposit of the solution onthe drum proceeding continuously while the machine is in operation. Thesurplus solution which is not picked up by the drum flows downwardlyover the front edge of the distributing plate or shelf and drops uponthe trough-shaped bottom of the vacuum chamber below the deliverynozzle. The film of solution adhering to the heating drum is carriedupwardly on the front side of the drum and downwardly on the rear sidethereof during which time all moisture contained therein is evaporatedowing to the heat of the drum, leaving only the dried residue ormaterial adhering to the drum. This dried material is continuouslyremoved from the drum before the respective part of the drum reaches thesolution feeding device which will be hereinafter described.

While lthe machine is in operation the working of the delivery nozzlemay be observed from the exterior by windows J arranged in the end headsof the vacuum chamber, as shown in Figs. 2, 3 and 6.

The solution to be dried is preferably sup -v plied to the nozzle underpressure by a feed device which may be connected with either end of thenozzle body while the other end is closed. As shown in Fig. 1, thesolution delivery pipe K is connected by a rotatable joint 7c with thefront end ofthe nozzle body while the rear end of the same is closed bya cover c. The means for delivering the solution under pressure shown inFig. 1 consists of a pump L which has its outlet connected Vwith thedelivery pipe K. If desired, the supply may be derived from an elevatedtank in which case gravity alone would furnish the required pressure.When it is desired to clean the-delivery nozzle the same is turneddownwardly from the positio-n shown in full lines in Fig. 7 to theposition shown by dotted lines in the same figure, whereby access may behad to all of its parts for thoroughly cleaning the same. lvhile thenozzle is thus turned downwardly for cleaning purposes access may be hadto the same through man-holes in the lower part of the vacuumv chamberwhich are normally closed by covers K2. The rotation of the solutiondelivering or distributing device into and out of its operative positionmay be effected by various means, those shown in Figs.1, 2, 4 and 6 ofthe drawings being suitable for this purpose and consisting' of a gearsegment M secured to the frontend of the nozzle body, arworm m engagingwith the gear segment, a shaft m1 journaled in bearings on the fronthead of the vacuum chamber and carrying the worm, and a crank Am2applied to said shaft for turning the same.-

'Ihe surplus solution which escapes over the front edge of thedistributing plate and drops upon the trough-shaped bottom of the vacuumchamber below the same is conducted into a receiver or storage reservoirN by one o r more return pipes n. This reservoir is referablyconstructed in the form of a horizont-al cylinder which is arrangedlengthwise below the vacuum chamber and the pipes n connect thelowermostpart ofthe trough or bottom of the vacuum vchamber with the topof the reservoir. Within this reservoir is arranged a stirrer oragitator which operates to mix cpitating. 'llhis agitator may be of any130 suitable construction that shown in Figs. 3 and 4 being referred andconsisting of a horizontal sha t O arranged lengthwise in the lower partof the reservoir and journaled at its opposite ends in stuffing boxbearings o, o1 in the front and rear heads of the reservoir and twolongitudinal dashers, beaters or blades 02 arranged lengthwise onopposite sides of the agitator shaft and connected therewith bytransverse arms '03. Upon rotating the agitator its blades move close tothe lower part of the reservoir or receiver and stir up anyl solidswhich have a tendency to settle, thereby maintaining the solution ofuniform consistency and in the best condition for delivery to theheating drum and its evaporation thereon. The agitator may be driven inany suitable manner, the gear wheel mounted on the front end of theagitator siiaft being the only part of the driving mechanism which isrepresented in the drawing. Arranged lengthwise on the inner side of thereservoir on opposite sides of the agitator are two bailie plates orflanges q which intercept the solution upon being moved by the agitator,thereby breaking up the solution and causing the same to be thoroughlymixed. F or the purpose of permitting the condition of the solution inthe reservoir and the operation of the agitator to be observed from theexterior, windows J1 are placed in the heads at the ends ofthereservoir, as shown in Figs. 2, 3 and 4. 0n its underside the reservoiris connected with the supply pipe R leading to the inlet of the pump,whereby the latter when in operation withdraws the solution from thereservoir and delivers the same against the underside of the heatingdrum by means of the nozzle. It will thus be noted that by this means aconstant circulation of the solution is maintained. The quantity ofsolution is however gradually reduced by reason of the heating drumpicking up a continuous film of the same in passing with its lower partin contact with the top of the stream flowing over the distributingplate. When the quantity of solution in circulation has diminished belowthe normal the same may be replenished by introducing an additionalquantity into the reservoir through one or more openings in the topthereof which are normally closed by caps or covers 1'.

The 'means shown in the drawings for removing the dried residue from theheating drum and discharging the same from the machine are constructedasfollows: S represents a horizontal conveyer trough arranged lengthwiseon the rear side of the vacuum chamber and provided at opposite endswith downwardly projecting discharge nipples, s, s. Within this conveyertrough is arranged a rotatable screw conveyer T one end of which isadapted to be connected with means for driving the same. t represents ascraper knife or blade which engages with the periphery of the heatingdrum between the conveyer trough and the return hopper of the vacuumchamber and which is adapted to remove the dried residue from theheating drum and direct the same into the conveyer trough. The materialthus removed from the heating drum and delivered into the trough ispropelled by the conveyer and discharged through one of the deliverynipples. The material may be discharged through either one or the otherof these nipples according to the position of the machine in the plantor other condition, the particular nipple not in use being closed by acover t and the conveyer being rotated in the roper direction forpropelling the material) to the delivery nipple which is in use. Anysuitable tra valve may be employed in connection with the deliverynozzle which is in use to permit the dried material to be dischargedfrom the machine but prevent the entrance of the external atmosphereinto the vacuum chamber. I

The scraper t or blade is pivotally suported at its lower end on thevacuum chamlier so that the scraper can be moved toward and from theheating drum and means are provided for yieldingly holding the plate inengagement with the heating drum when the machine is in operation whichmeans are constructed to permit not only of regulating the pressure ofthis scraper against the drum but also permit of moving the blade awayfrom the drum when required.

To permit of observing the operation of the scraper and conveyer one ormore windows t2 are arranged on the rear side of the vacuum chamberabove the conveyer which windows are capable of being cleaned by meansof a wiper t capable of being operated from the exterior of the vacuum camber.

The drying of the material on the heating drum is facilitated byconnecting4 the vacuum chamber with a condenser, vacuum pump or otherexhausting device whereby the vapors are forcibly withdrawn from thevacuum chamber. The vapors escape through four va or outlet nipples Uarranged on the nected centrally on its upper side by a vapor pipe uwith a condenser, vacuum pump or other exhausting device not shown inthe drawings. Extending downwardly into each separating chamber onopposite sides of its vapor pipe are two separating pipes WV which areconnected at their upper ends with corresponding vapor outlet nipples Uof the vacuum chamber while their lower ends terminate above the bottomof the separating chamber and are provided with serrations or notchesfw. Each of the separating chambers is filled with liquid, preferablywater, to a point above the lower end of the separating pipe the levelof which may be determined by means of gages X applied to said chamber.When the exhausting device connected With the vapor pipes is working,the vapors drawn from the vacuum chamber pass through the nipples U,thence downwardly through the pipes W, thence upwardly through theseparating chamber and thence outwardly through the main vapor pipes. Asthe vaf pors pass upwardly from the separating pipes through theseparating chambers to the vapor outlet pipes the same nieve through thebody of water in the separatingchamber, whereby some of the vapors arecondensed andany dust or light dried residue which has been drawn overfrom the vacuum chamber is taken up by the water and separated from thevapors, thereby saving the same. By serrating the lower edges of theseparating pipes, the vapors in passing around t-he lower- `edge of thesaine are disintegrated or broken up, thereby insuring Vthoroughseparation therefrom of the light particles of dried umaterial andpreventing the same from escaping with the vapors as would be liable tooccur if the lower edge of the separating pipes were straight andpermitted the vapors to pass around the same in the form of largebubbles. When the separating water in the separating chambers becomesheavily loaded with dust particles, the same may be withdrawn throuohdischarge .pipes x1 having valves m2 and returned to the reservoir to beagain subjected tothe vacuum-"drying operation hereinbefore described.Access to the interior of each separating chamber for cleanmanhole inits side which-.is normally closed.

ing and inspection may be .had through a bya cover w1, as shown in Figs.I and 2.

"Instead of distributing or delivering the solution to the drum andagitating the same by the means shown in Figs. Il?, `this may beeifected by the modified means which are shown` in Figs. 9 and 10 -andwhich'are constructed as -follows: Y represents the tubular body of adelivery nozzle arranged lengthwise below the heatingvdrum and having alongitudinal slot Y1 in its upper side and supported inthe end walls ofthe vacuum chamber. In its upper side the delivery nozzle or pipe isprovided with two longitudinal upwardly diverging side walls y, g/ andtwo end walls y1, y1. The lower edges of the side walls are separated byan intervening longitudinal slit whereby the tubular body communicateswith the basin or space between the walls y, y1. The upper ends of theside walls 1/ are separated from the periphery of the heating drum by anintervening space, as shown in F ig. 10. Each of the end walls isprovided with a guard rib or packing strip y2 which engages with theperiphery of the heating drum and prevents the liquid from {iowing overthe ends of the' basin. The solution passes from the tubular body Yupwardly through the slit in the bottom of the basin and `after illingthe latter overflows opposite longitudinal edges thereof. The heatingdrum rotates with its periphery in contact with the flowing body ofsolution in the basin and picks up a thin film of the same which isdried thereon and subsequently removed. The surplus of the stream fallsfrom opposite edges of the trough and is returned to the reservoir to beagain circulated in the manner hereinbefore described. l

In order to prevent the solution from settling in the delivery basin anagitator is located therein which preferably consists of alongitudinally reciprocating bar Z arranged lengthwise in the basin andextending at one end through t-he basin and nozzle body to the exteriorof the machine and a plurality of triangular wings, blades or flights.e1 secured transversely to the longitudinal bar. The meansorreciprocating this agitator shown in Fig. 9 of the drawmgs consists ofa yoke z2 secured to the end of the bar Z, and a rotating crank .23provided with a slide at movable transversely in said yoke.

In the use of this machine the total amount of solution which is incirculation in the machine does not exceed an amount which would ill thereservoir up to its lling openings. By this means the entire batch ofsolution can be held in the reservoir, thereby avoiding accumulating anyof the solution in the lower part of the vacuum chamber and preventingany solution from over-flowing from the latter into the conveyer -troughcontaining the dried material.

I claim as my invention:

l. A vacuum drying apparatus comprising a` vacuum chamber, a deliverypan independent of the bottom of said chamber arranged inthe lower partof the vacuum chamber and adapted to support a stream of the condensate,a heating drum rotatable within the upper part of the vacuum chamber andadapted to dip its lower part into the condensate within said pan, meansfor supplying said pan with condensate in excess of the amount which thedrum is able lo carry away and thereby cause the cru-oss coudensate toflow over the edge of the pan, and a catch basin communicating with thelower part of the vacuum chamber and adapted to receive the surpluscondensate escaping from said delivery pan.

2. A vacuum drying apparatus comprising a vacuum chamber, a horizontalheating drum rotating vertically within said cli-ainber, and a nozzlefor delivering the solution to the periphery of the drum having atitbular body arranged lengthwise below the drum and provided with alongitudinal delivery slot on its upper side, a distributing shelfseparated from the periphery of the drum by an intervening space andarranged on said body infront of its slot1 and a dam arranged on saidbody in rear of its slot and extending closer to the periphery of thedrum than said shelf, substantially as set forth.

3. A vacuum drying apparatus comprising a vacuum chamber, a horizontalheating drum rotating vertically within said chamber, and a nozzle fordelivering the solution to the periphery of the drum having a tubularbody arranged lengthwise below the drum and provided with a longitudinaldelivery slot on its upper side, a distributing shelf separated from theperiphery of the drum by an intervening space and arranged on said bodyin front of its slot, a dam arranged on said body in rear of its slotand extending closer to the periphery of the drum than said shelf, andguard flanges arranged transversely at opposite ends of said shelf andengaging the periphery of the drum` substantially asset forth.

4. A vacuum drying apparat-us comprising a vacuum chamber, a horizontalheating drum rotating vertically within said chamber, and a movablesolution delivery nozzle arranged adjacent to the underside of theperiphery of the drum and capable of being moved with its outlet towardthe drum for delivering the solution to the drum or with its outlet awayfrom the drum to permit of cleaning the nozzle, substantially as setforth.

5. A vacuum drying apparatus comprising a vacuum chamber, a horizontalheating drum rotating vertically within said chamber, and a nozzlearranged below the drum and adapted to deliver the solution to theunderside of the periphery of the drum having a rotatable tubular bodyprovided with an outlet adapted to face either toward or away from theperiphery of said drum, substantially as set forth.

6. A vacuum drying apparatus comprising aV vacuum chamber, a horizontalheating drum rotating vertically within said chamber, a nozzleA fordelivering the solution to the periphery of the drum having a rotatabletubular body provided with an outlet adapted to face either toward oraway from the periphery of said drum and means for turning said bodycomprising a worin segment secured to the body, a shaft, a worm arrangedon the shaft and meshing with said segment, and a crank arranged on saidshaftIl substantially as set forth.

7. A vacuum drying apparatus comprising a vacuum chamber, a rotatableheating drum arranged in the upper part of said chamber, a delivery panindependent of the bottom of said chamber arranged below the drum andadapted to support a stream of condensate against the underside of thedrum, a pump for supplying said pan with condensate in excess of thequantity which `can be carried away by said drum, and a i catch basinarranged below said pan and receiving the surplus condensate from saidpan and supplying the same to said pump or returning t e condensate tosaid pan.

8. A vacuum drying apparatus comprising a vacuum chamber, a heating drumarranged in said chamber, a nozzle arranged in said chamber and adaptedto deliver a stream of solution so that the drum will pick up a filmthereof while the surplus drops to the bottom of the chamber, and areservoir connected with the lowestpart of said chamber and adapted toreceive the surplus solution therefrom and an agitator arranged in saidreservoir, substantially as set forth.

9. A vacuum drying apparatus comprising a vacuum chamber, a heating drumarranged in said chamber. a nozzle arranged in said chamber and adaptedto deliver a stream of solution so that the drum will pick up a filmthereof while the surplus drops to the bottom of the chamber, areservoir connected with the lowest part of said chamber and adapted toreceive the surplus solution therefrom, and an agitator arranged in saidreservoir and comprising a shaft, blades mounted on the shaft, andbaille plates arranged on the inner side of the reservoir adjacent tothe path of said blades, substantially as set forth.

10. A vacuum drying apparatus comprising a vacuum chamber, a verticallyrot-ating drum arranged in said chamber, and means for applying thesolution to be dried to said drum comprising a nozzle which is arrangedbelow the drum and supports a stream of solution in contact with theunderside of the drum and which terminates at its opposite ends short ofthe ends of the drum.

11. A vacuum drying apparatus comprising a vacuum chamber, a verticallyrotating drum arranged in said chamber, and means for applying thesolution to be dried to said drum comprising a nozzle which is arrangedbelow the drum and supports a stream of solution in contact with theunderside of the drum and which terminates at .its opposite ends shortof the ends of the drum and y transverse flanges arranged at oppositeends of the pan and projecting toward the periphery of the drum.

12. A vacuum drying apparatus comprising a vacuum chamber, a'rotata'ble'heating drum arranged in said chamber ,and having hollow trunnionsjournaled in bearings on the same, a stationary steam inlet pipearranged in one of the trunnions, a stationary outlet pipe arranged inthe other trunnion, a scoop arranged obliquely on the inner side of thedrum with its front end in` advance of its rear end, and an intermediatepipe lconnecting the rear end of the scoop with the outlet pipe,substantially as set forth.

1 3. A vacuum drying apparatus comprising a vacuum chamber, a rotatableheating which is not picked up by the drum is discharged' into the lowerpart of said chamber, and means for withdrawing the con-v densate fromthe bottom of the Vacuum chamber and delivering the same to said pan.

Witness my hand this 11th day of February, 1908.

Witnesses Tramo. L. Pori, ANNA HEIGIS.

OLIVER s. SLEEPEaf

